The present invention relates to DC to DC converters, and in particular, to multi-phase converters which produce a DC output voltage at the common output of a plurality of coupled switching power supplies, for example, a plurality of buck converters.
Multi-phase converters are known. In a typical multi-phase converter, for example, a multi-phase buck converter, a plurality of buck converters are provided each having their output inductors coupled to the output node. In a typical application, each buck converter is controlled by a control circuit and may be operated such that a control switch of each buck converter switching stage is turned on at a different time than the other phases. In this way, each phase sequentially provides power to the load, reducing ripple and reducing the size of the output capacitance.
With multi-phase converters, it is desirable to be able to control the current provided by each phase, and in particular, so that the currents provided by each phase are equal so that no phase provides too great a current compared to the other phases. This contributes to increased efficiency, longer component life and prevents device destruction.